Deployed forces face an increasing number of threats from their adversaries. Of chief concern is the Improvised Explosive Device (IED). IEDs are generally hidden near or underneath roadways and remotely detonated by an operator stationed nearby. While remote detonation methods include radio frequency, infrared and hydraulic actuators, by far the more difficult to detect is the use of the common command wire.
The command wires are typically embedded in the ground where they can neither be seen or readily detected. Thus, convoys have routinely been attacked by improvised explosive devices which are buried and camouflaged so that neither the explosive nor the command wire is readily observable.
Since RF detonating devices can be sensed by detecting RF energy from the devices, these RF devices can be countermeasured because their existence is ascertainable. However, the use of wires to detonate explosives from for instance distances of 100 to 500 feet provide a stealth component to IED detonation because the wires themselves are very thin and easily hidden or buried.
Thus, remote detection of command wires embedded in towns and cities above and below ground is a daunting task. Since microwave UHF signals and VHF signals cannot effectively penetrate into the infrastructures of the city or below ground, one has to investigate what near field approaches can be applied that operate in a frequency range which will in fact penetrate local objects in the ground.